Field of the Invention
The present invention relates generally to polyoxometalates and, more specifically, to polyoxometalates attached to porous polymer substrates.
Description of the Prior Art
Polyoxometalates (POMs) have been used as oxidation, polymerization, and hydration catalysts for over 20 years. They have a very strong acidity approaching the superacid region, and are efficient oxidants, exhibiting fast reversible multi-electron redox transformations under mild conditions (Kozhevnikov, Chem. Rev., 98,171-198 (1998)). These properties are advantageous for the catalytic destruction of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs). For instance, the FeIII[H(ONO2)2]PW11O395− (POM) is known for its aerobic catalytic oxidation of HD (sulfur mustard) (Okun et al., J. of Mol. Cat. A: Chem., 246, 11-17 (2006)). The real-world performance of POMs for such applications, however, is often limited by the low surface areas of typical solid-state forms of this material, resulting in poor catalyst utilization. This limitation can be overcome by suspending the POMs into a polymer matrix. Unfortunately, the inability of the POM to stay suspended in the polymer over time leads to unpredictable catalytic activity. Such effects as mechanical strength and thermal and chemical stability are often difficult to realize by simple doping of POMs into polymer matrices. The current research is focused on maintaining the innate catalytic properties of POMs in the solid state after attaching POMs to a porous polymer. Covalently or ionically bound POMs will limit inherent aggregation while preserving long-term stable catalytic activity representative of the parent POM, with the added benefit of the polymer backbone which will allow the formation of films, coatings and composites.